Mobile devices, such as mobile (cellular) telephones, PDAs (Personal Digital Assistants), laptop computers, and (portable) gaming consoles increasingly have multiple functions. Modern mobile telephones, for example, are not only suitable for making telephone calls but often also include a calculator, a calendar, and even games. Mobile phone games are typically designed for a single player, involving only the mobile device they are played on. However, some types of games require multiple players, each player using his/her own device. Before a multiple player game can begin, the players have to be selected and, accordingly, their mobile devices have to be identified.
It is possible to identify other mobile (or non-mobile) devices using a stored phone list containing the telephone numbers of other mobile devices and the respective names of their owners. However, the phone list contains no information regarding the availability and proximity of the other mobile devices. If a multiple player game is to be played with a group of players who are located in each other's vicinity, for example within viewing distance, the mobile devices of that group have to be identified in another way. Of course it is possible to manually enter the telephone numbers of participating mobile devices, if these numbers are known. However, this is cumbersome and prone to errors, in particular when the telephone numbers have to be read aloud.
Using Bluetooth© for identifying devices is also cumbersome. An elaborate procedure is required in which another device is selected from a so-called device discovery list and a password may be required to enable Bluetooth© pairing. This procedure is neither quick nor effortless.
Accordingly, there is a need for a simple yet effective identification mechanism for mobile devices located in each other's vicinity.
Such an identification mechanism can also be used in mobile devices other than mobile telephones, for example in PDAs, laptop computers and so-called notebook computers. An identification mechanism may not only be used in gaming applications, as PDAs and similar devices may in general need to identify other devices in order to initiate a transaction between the devices. An example of a transaction is exchanging information, such as data files, calendar appointments, and other information.
The identification mechanism would primarily be used for (mobile or non-mobile) devices which are located in each other's vicinity, as remote devices would not likely be involved in a multiple player game or data exchange. In particular, it is often desired to invite (the owner of) a device to join a game, to engage in gaming interaction, to exchange a data file, to exchange an electronic business card, to carry out a financial transaction or to exchange calendar data when (the owner of) the device is in view. For the invited device to join the game or exchange data, it first has to be identified. Accordingly, there is a need to automatically identify proximate devices and to subsequently activate a service, such as a game, involving the identified proximate devices.
International Patent Application WO2009/014438 (TNO/KPN) discloses an application server that uses a method of identifying proximate mobile devices by means of sensory identifiers. A detected sensory identifier, such as a particular sound or image, may be verified in the server. Such a verification by the server makes it unnecessary for the mobile devices to contain verification software and/or hardware, thus keeping the mobile devices relatively simple and hence inexpensive. The mutual identification resulting from this known method is typically used to initiate a game, transaction or other activity. This further activity requires suitable software running on the server. The obvious choice for the server for carrying out the further activity (game, transaction) resulting from the identification would be the server used for the identification process. However, when different servers are provided for performing several different further activities, several servers would be used, each server providing both the identification and the resulting activity. This would, however, require multiple instances of the identification process. In addition, each server would have to have the resources (memory, processing capacity) to run both the identification and the activity applications, thus making the servers relatively expensive.